Why is my game asking me to return Rachels car If I already returned it a long Time ago? And everytime they say i have unlocked a new car I don't get them? And have got my own car A toyta celica And she says to return it how do I return it? Can you please help...

My Brother Wants to start a career on the game but I still have mine on there, how do i start a second carerr without losing my mine? will I lose my prevoius file when I start a new one,or will I have a second file without losing it? Could you please reply,Thanks.